Intense visible light or radiation of shorter wavelength, i.e., between about 200 and about 400 nanometers (ultraviolet radiation), from the sun or from artificial light sources poses a significant risk of eye injury. The eye is particularly susceptible to damage from exposure to ultraviolet radiation because the damaging radiation cannot be sensed by the light receptors in the eye. Thus, ultraviolet (UV) radiation is invisible to the eye, and the injury is not apparent until after the damage is done. While the UV radiation component of sunlight can damage the eyes without proper precaution, the majority of cases of UV radiation eye damage arise from the use, or more appropriately the misuse, of artificial sunlamp products in the home or in commercial tanning salons. Responsive to that fact, federal regulations have been promulgated to specify safety standards for the manufacture and use of UV emitting products. One of those regulations (21 C.F.R. .sctn. 1040.20) requires that protective eyewear be provided and used with all UV emitting lamps. To comply with these regulations some lamp manufacturers and many tanning salon proprietors have been supplying customers with reusable goggle-type protective eyewear, which although functional to protect the eyes, are uncomfortable and not size-adjustable to fit each prospective user. Moreover, reusable protective eyewear presents certain sanitary problems--it can serve as a means for spreading communicable eye diseases of both microbial and viral origin. This fact, coupled with the prevalent fear of contracting certain viral infections, prompts many users of UV light emitting products to refuse to use appropriate protective eyewear. Reusable goggles, although available to the customer, are often simply not used.
Clearly the availability of a disposable, adjustable, and inexpensive eye protector for use with UV emitting devices and for use in other circumstances requiring temporary protection of the eye from potential eye irritants, would meet important public health and safety needs. Not only would such a device promote the use of appropriate eye protection at home and in the increasingly popular tanning salons, but it would also help to minimize the spread of disease possibly associated with reusable protective eyewear.
Several early inventors faced with the need for easy-to-use eye protectors developed and patented ocular patch-type protective eyewear in both disposable and reusable forms. See, for example, the eye protectors or eye shields disclosed in U.S. Pat. Nos. 2,165,668; 2,283,752; 2,572,638; 3,068,863; and 2,527,947. While the patch-type eye protectors disclosed in those early patents function to protect the eyes from potential eye irritants and harmful radiation, none of them were designed (1) to selectively transmit at least a portion of visible light so that the user can "see" while wearing the protective eyewear; (2) to be shaped to conform to the facial tissue adjacent the eye; or (3) to allow for substantially unhindered eye lid movement when the eye protector is positioned over the eye.
More recently, U.S. Pat. Nos. 4,739,002 and 4,701,962 (hereinafter referred to as the "'002 and '962 patents," respectively) disclosed disposable eyewear in which a conical eye protector is formed by overlapping and adhering portions of ovoid or circular film segments. Those film segments are formed to contain ultraviolet absorbing compounds, yet they allow sufficient visible light to pass through to enable the user to "see" while wearing this protective eyewear. The patented eyewear represented a significant advance in the field of protective eyewear because they were disposable, they allowed for some vision in use and they covered only the eye and the facial tissues adjacent to the eye.
The present invention is based on applicants' discovery that the film segments used for forming protective eyewear similar to that described in U.S. Pat. No. 4,739,002 can be formed to a novel shape that provides significant improvement in eyewear functionality. Eyewear formed from film segments in accordance with this invention (1) fit better to the facial tissue adjacent to the eye; (2) have an increased field of vision; (3) provide more room to open and close the eye; (4) cover less of the brow area adjacent to the eye; and (5) are more resistant to unintended damage during user manipulation of the segment to form the eyewear.
The improved film segments of this invention are formed to have a novel shape in plan view including a C-shaped edge segment and a W-shaped edge segment cooperating to define a peripheral edge. The general shape hereinafter is referred to as the "CW shape" and the shaped film segment is hereinafter referred to as "CW-shaped film segment". In one embodiment the film segment comprises a polymeric film having a radiation transmittance value of less than 1 for at least a portion of incident ultraviolet, visible or infrared radiation. A contact adhesive is applied to a locus of the segment including at least a portion of the peripheral edge defined by the W-shaped edge segment. The film segment is formed into an asymmetric conical shape by overlapping the portions of the film segment defined by the W-shaped edge segment. The adhesive at the locus of the W-shaped edge segment holds the overlapped portions in place and thus works to hold the segment in the conical eyewear shape. The eye protector is then located over the eye in an adhesively retained position. In practice, a pair of protectors are used, each one positioned to cover each eye.